Analysis:Colin Kaepernick got sacked 52 times last season, more than any 49ers quarterback ever in a season. After seven different starting combinations in 2014, stabilizing the line is a must, and it begins with replacing Pro Bowl left guard Mike Iupati (now on the Arizona Cardinals). If Brandon Thomas is fully recovered from the knee injury that voided his rookie season, he could be the favorite at left guard, although free-agent veteran Erik Pears will challenge him, as might Marcus Martin, who will also vie for the center spot with Kilgore. Pears also is suited to as a swing tackle behind Staley and Davis, whose 2014 season uncharacteristically was hindered by injuries.

Draft possibilities:Adding a stud tackle could be in order, seeing how bad the line suffered without Davis. Shoring up their interior is also wise with Iupati gone and Alex Boone entering his revised contract’s final year. Among the top-rated tackles are Brandon Scherff (Iowa), Austin Peat (Stanford), La’El Collins (LSU) and Donovan Smith (Penn State). A high pick seems unlikely for a guard, because the 49ers believe Thomas would have been a higher-round draft pick last year if he hadn’t torn an ACL and fallen to them in the third round.

GM Trent Baalke quotes: “We knew (2014) would be a redshirt year for (Thomas). But at this point, he looks very good. He s come off the knee injury very well. He s strong. He s moving extremely well. He s a veryengaged guy, very focused on what he needs to do and wants to do at this level. Can he align at tackle? He s proven in the SEC he can against the No. 1pick in last year s draft. Would we feel comfortable putting him out there?Yeah, but we also have Joe Staley sitting out there, Anthony Davis on the other side and a hole (at left guard) to fill inside. We brought Erick in to compete at that position as well, a guy that s had a lot of experience starting. We ve got Marcus Martin who started two years at guard at USC and made the switch to center. Kilgore coming back at center. We feel very good with where we re at in regards to the OL.”